1. Field of the Invention
The present invention relates to a contactless monitoring system and, more particularly, to a monitoring system that can be used both for monitoring an individual seated in a chair and for monitoring an individual lying in a bed. The invention additionally relates to an improved structure for removably mounting a monitoring system on the seatback of a chair. Because of its versatility, this invention could also be used to monitor a door, room, entry way, walker, hallway, bathroom or toilet.
2. Discussion of the Related Art
As the population ages, an increasing number of people are developing dementia and require continuous supervision. Even while seated or lying in bed, patients with dementia must be monitored to ensure that they do not fall from the chair or bed, either inadvertently or by attempting to get out of the chair or bed unassisted.
In a homecare situation, this requires that the caregiver be at the patient""s side constantly, subjecting the caregiver to severe psychological stress, physical deterioration, burnout, and even premature death. The need has therefore arisen to help caregivers monitor patients and still be able to rest, perform household chores, etc. without worrying about the patient""s location and safety.
In a hospital, nursing home, hospice, or other health care institution, it is impracticable to have a staff member assigned to only one patient. However, patients in health care institutions are often predisposed to falling. For many of these patients, who may be frail or ill to begin with, a minor fall constitutes a significant health risk. Accordingly, a simple, inexpensive, contactless method of monitoring the movements of a patient without requiring constant observation or restraints is needed.
Numerous methods for preventing falls from chairs currently exist. For instance, physical restraints are commonly used to prevent a patient from exiting a wheelchair or hospital bed or other apparatus. Although the use of physical restraints is effective in confining the individual to a specific area, there are psychological side effects that result from the individual""s perceived loss of his or her freedom and dignity, as well as the potential for physical injury resulting from struggling to be free of the restraints. As a result nursing homes and hospitals are required to become restraint free while maintaining a safe environment for patients and residents.
Electronic monitoring devices help alleviate many of the negative effects of physical restraints and have a wider range of uses. These monitoring systems typically fall into three major categories: pressure detection pads, physical attachment to a monitor via string or cord, and intensity-based measurements of transmitted energy beams. These solutions are problematic in terms of cost; patient comfort; high numbers of errant, or nuisance, alarms; simplicity; and mobility.
For example, pressure detection pads must be replaced frequently because they are easily damaged and rendered inoperable. They also require a person to have already left his or her place before sounding an alarm, rather than warning of imminent danger. Conversely, lightweight people, such as many frail elderly people, can trigger the alarm by making small movements that redistribute their weight. To compensate, these systems must have time delays before alarming when a person leaves the bed or chair.
Physical attachments to monitors by way of cords and clothing clips are irritating to patients because they are visible to them and can wrap around limbs and cut off circulation. These products are not suitable for bed monitoring of an active person. They are also easily removed by the monitored person or other residents or patients, rendering them completely ineffective. Distance adjustment is cumbersome. Staff must therefore constantly check to ensure patient compliance. Furthermore, even where there is compliance, an inadvertent movement pulling out the attachment requires staff attention and resetting the monitor even when the patient returns to his or her location immediately.
Systems relying on intensity-based measurements of transmitted energy are relatively complex. Under one type of system, a transmitter is positioned in one location near the patient and a receiver is positioned in a second location so that it continually receives the transmitted beam when the patient is in a desired position. If the individual moves outside the desired position, the beam is broken and an alarm is triggered. Although this approach does not require any of the restrictive methods as required in the two previous categories and has a wider range of applications, it only indicates the presence or absence of the monitored individual in the transmitted area. These systems are not portable and are not effective for both bed and chair monitoring because of the difficulties in measuring energy intensity. They can be confused by various environmental energy beam transmissions, a person""s clothing, size and shape. Furthermore, it cannot detect small changes in the patient""s position, such as slumping.
The complexity and sensitivity of a monitoring system relying on energy intensity-based measurements also requires that transmitters and receivers be permanently or semi-permanently mounted in a specified location in order to adequately monitor the area. This latter requirement renders the system poorly suited to monitor either a patient seated in a chair or a patient lying in a bed. In fact, no known electronic monitoring system is configured to be readily adaptable for both types of measurement using at least some of the same equipment. In addition, known chair monitoring systems are not easily mountable on the back of a chair in a manner that provides them with a wide range of monitoring ability yet still permits them to be easily mounted on a wide variety of chairs.
The need therefore has arisen to provide a monitoring system which is effective, provides instant alarms while still in the bed or chair, eliminates strings, cords, pads and patient attachments, does not interfere with normal patient movement or generate an alarm due to such movement, is simple to set up, install, and use, does not require permanent installation on furniture, and/or can be easily reconfigured from one monitoring mode, such as monitoring a patient seated in a chair, to another monitoring mode, such as monitoring a patient lying in a bed. The ideal monitor meeting this need would be adaptable to virtually any conceivable patient orientation, such as the monitoring of a patient lying in a bed positioned in an open space, along a wall, or in a corner.
The need has additionally arisen to provide a monitor that can be easily mounted on the back of a chair in a manner that provides a wide range of monitoring ability yet permits easy mounting on a wide variety of chairs.
A patient monitoring system having several advantageous features is disclosed. The same can be used in different locations and/or in different monitoring modes. For instance, it is usable on both a chair and a bed. When used on a chair, a base unit of the system can be used in conjunction with a chair cover to attach it to the chair with ease. The base unit preferably relies on energy intensity-independent measurements to determine whether a patient is within a defined area of the chair, and an alarm is generated when the patient is not in the defined area.
When used on a bed, the base unit operates in the opposite manner of the chair monitor and can be connected to a remote unit and one or more plug-in modules. The base unit, remote unit, and plug-in module(s) can send and receive signals, and, in conjunction, are able to determine whether a received signal is within a desired perimeter, and thus whether a patient is within a monitored area. The base unit can generate an alarm if a received signal is outside the desired parameter.
A method of using such a system, in which a base unit is alternatively attached to two different structures such as a chair or a bed, is also described. In addition, alternate strategies for monitoring a patient, depending on whether the patient is in a chair or in a bed, are discussed, and a switch for changing from one strategy to the other is disclosed. Preferably, the system is switchable between monitoring modes such that it relies on a volumetric-based measuring approach when the patient is seated in a chair and a perimeter-based measuring approach when the patient is lying in a bed.